04:50
Ratio and Proportion: Simplifying the Comparing of Fractions by Cross Multiplying
This clip explains that cross multiplying is a shortcut which allows us to determine if two fractions are the same. The fractions are compared by multiplying the numerator of each by the denominator of the other. If the products are the same, then t...
03:26
Ratio and Proportion: Problem In Which The Denominator Is Missing, A
This clip explains that, whether it's a numerator or a denominator that's missing, in order to be sure that "
we really have a proportion...the cross products must be equal."
04:49
Ratio and Proportion: Solving Word Problems Involving Proportions
This clip presents two word problems involving proportions which require dividing both sides of an equation by the same number. The answers are checked by forming cross products which are equal.